A. O. Smith. Raising the level of thermal efficiency (EF) to 90%, the Next Hybrid high-efficiency gas water heater combines a tankless design with a small buffer tank to maximize benefits of both technologies. A patented heat-transfer process routes the exhaust gas from the tankless engine to the buffer tank to extract additional heat. While performing like a tankless water heater, the model also can handle peak demands with the buffer tank. The Next Hybrid is eligible for federal tax credits of 30% up to $1,500 through 2010. The model has a footprint similar to conventional water heaters and features standard water and gas connections for convenient retrofitting. 414.359.4000. www.aosmith.com.